Gas producer



A. E. BLAKE 2,381,200

GAS PRODUCER Filed Jan. 22, 1943 2 Sheets-Sheet 1 m m m m Aug. 7, 1945. A. E. BLAKE 2,381,200

GAS PRODUCER Filed Jan. 22, 1945 2 Sheets-Shet 2 1 win A u IIlIlIIlIlIlIIIII/I- IN VEN TOR.

ahala/v5) I and means whereby the motor Patented Aug. 7, 1945 umrso STATES PATENT OFFICE AlfredEBlflhWeltOalMlE-I.

Application January 22, 194:, Serial No. 413,152

6 claims. (01. 48-87) This invention relates to gas producers. Ob-

jects of the invention are to avoid injury to the p ucergrateandtoobtainamoreuniform and continuous operation of the producer, to reduce the effects of carelessnes and unreliability of operators, and to obtain maximum gas production with minimum fuel and power consumption and minimum labor.

The invention is especially intended for dry grate producers which use fuels of low volatile content. such as coke and anthracite coal, and which have mechanical grates, that is, grates which, or apart or parts of which, are movable for causing ashes to be discharged downward through the grate and are operated, either continuously or intermittently, by a suitable motor,

usually an electric motor.

In the operation of such gas producers, it is for best results and for protection of the grate that a, layer of ashes of suflicient thicknes be maintained on the grate between it and the hot burning fuel above. If the layer of ashes becomestoothininanyparhtheg'rateisdam aged by the excessive heat and may he so seriousb damaged, even to the extent of being-practicaldestroyed. as to allow and fuel down through It has been customary, therefore, in the operation thickness and whereby, if the temperature in any art of the ash bed at such level above the grate exceeds a certain maximum. the grate motor is stopped. is started again uncontrolled flow of ash.

the grate, resulting in, serious stoppa e in the operation ofthe producer.

whenthcashbedhasbeensuflicientlyincreased.

The invention includes the provision of means for quicklycoolingandatthesametime increasingthethicknessofapartoftheashbedwhich hasbecometoothin,andmeansfor givingan 'alarmtocalltheoperatorwhenthebedhasa too thin part, and means for making a record of the temperature of different parts of the ash bed at the selected level.

A full understanding of the invention can best be given by a detail description in connection with drawings showing a gas producer embodying the various features of the invention, and such a description will now be given in connection with the accompanying drawings, in which- Fig. 1 is a sectional view of a gas producer embodying the various features of the invention in the form now considered best; Fig. 2 is a partly tic view showin a sectional piano! the furnace chamber of the producer taken on line 2-2 of Fig. 1, and the multiple record indicating and recording controller, and showing diagrammatically the motor stopping and re-starting means and the signal horn and the various electrical connections;

Fig. 3 shows a portion of a record sheet with suppositional record markings thereon;

Fig. 4 is an enlarged detail view, mostly in section, of a part of the multiple record con troller; and v Fig. 5 is a detail Referring to the drawings, Fig. 1 shows a gas producer having a substantially flat stepped mechanical grate of the kind shown by Figs. 3 and n 4 of my Patent No. 2,255,373. The grate has a stationary annular outer plate III which has a downwardly-offset inwardly-extending art Illa, a central plate II at the level of plate III, and a concentrically revoluble annular plate I2 between and at the same level as and spaced from the plates Ii and I I, and which has a downwardlyoifset inwardly-extending plate I2a. .The width of plate I2 is less than the distance between plates II and II. so that annular ash discharge openings II and II are left between the plates, and the lower plate Ila extends under the plate I2 and' lower plate I20 extends under-plate ll, so that ash dropping through the o enings II and I! will pile up on andremain on plates Ila and Ila. The plate I2 is mounted by means of a ball bearing II on an annular support It surrounding a central post It which carriesthe cenview of an alternative temperature-responsive element.

II and over the cap plate 20 and which carry 2- a,ss 1,aoo

the opening l6 and over the plate It and which each a rake, or plough, 26 extending down through the opening l6.- As explained in my Patent No. 2,255,373, the ploughs push ashes from the plates Ilia and I2 and the arms act to move ashes onthe plates I0, I! and I2 toward the openings l5 and I6, so that by rotation of'plate l2 the ashes. are caused to be fed gradually downward through the grate to fall into the ash pit. The

rate of ash discharge depends on the speed at which the plate I2 isrotated, and the rate of dis: charge determines the depth of the ash bed main- 7 tained on the gra The producer chamber has the usual water,- jacketedwalls, a fuel feed opening 30 in its top wall, a gas take-oil pipe 3| leading from an opening in the top wall, and a pipe 32 through which a mixture of, air and'steam is supplied to be discharged into the ash pit from discharge holes in a circular pipe 33 mounted beneath the grate. A blast of heated air is supplied to the pipe 32 from a suitable source, and steam from a steam drum connected to the top and bottom of the producer chamber wate -jacket, or from other source, is supplied to the pipe 32 as usual to form the proper air-steam mixture. The top chamber wall is shown as having the usual normally closed poke-hole fittings 36.

The producer furnace is provided with a plurality of thermo-couple pyrometer tubes mounted to extend through the furnace wall into the ash bed space at points spaced circumferentially and at a distance above the grate to be somewhat below the normal level of the top of the ash bed. If the ashbed is tobe maintained Q about 7 inches above the grate, but the level above the grate of the tubes maybe more or less than 7 inches within a considerable range according to the normal depth of the ash bed and or other temperature-responsive elements used. An additional pyrometer tube 4| is mounted within the hollow post I9 to extend up through 'th cap plate 20 to measure. the temperature at The conductors from this tube, extending down through the post a middle point of the ash bed.

into th ash pit and out through the side wall of the pit, are protected by a t be' 42.

. The conductors from each ofthe tubes in and -with a thickness, or depth, of about Qinches, the pyrometer tubes aremost desirably set at the characteristics of the thermo-couple tubes" from the tube 4| lead to a multiple indicating and s recording potentiometer controller 46 having a member 46 which 'is moved along a temperature marked scale marked record sheet 43 under control oteach oi the several pyrometer tubes in sequence in successive time periods. The member 46 carries a pointer 43 for indicating the temperature on a scale 41 and a printing wheel 33 which has numerals or other characters indicating the several pyrometer tubes and is turned for each move-.

ment of member 46 to bring-into printing posi tion the character indicating the tube under control of whichmember 46 has made that move ment, a printing movement being then eflected to press the positioned character against the chart. The temperatlu-es measured by the several tubes are thus indicated by the pointer and recorded n the chart insequence' in each successive time 41 and over a correspondingly.

period, the chart being given a suitable forward feeding movement. Such multiple indicating and recording controllers are well known instruments and-are made by several established concerns. As theinstrument in and by itself forms no part of the present invention, it needs no further description.

When any on'e-of-the 'pyrometer tubes is sub- Jected to a temperature above a certain predetermined maximum, the circuit to the grate motor is opened by means actuated by the controller member 46 when the member is moved to a position corresponding to such maximum temperature. For this purpose. as shown by Fig. 2, the circuit to the grate-motor includes a toggle-operated switch which is opened by the enerswitch-opening solenoid '66- includes a normally open switch 53 mounted on the controller 45 in position to be engaged by and closed by a finger 66 extending from the member 46 when the member 46 has been moved to the position'corresponding to said maximum temperature. The finger 59 is a one-way trip finger, being pivotally mounted on the member 46 and free toturn to the right as viewed in Figs. 2. and 4, so that if it has been moved beyond the engaging member of the switch 66 it will when it strikes the switch mem her on return movement or member 46 swing away from the switch member and down soas to pass beneath it. The switch 53 is, as shown in Fi 2, pivotally mounted sons to permit the finger 59 to pass onbeneath it in itsforward movement, and it is adjustable lengthwise of the scale for varying the temperature at which the operation of the grate motor is stopped.

An electrically p rated horn or other sound signal device 60 is connectedlin thecircuit to solenoid 56 so that a sound signal will be given whenever the circuit is closed to cause the motor circuit to be opened.

The ash bed temperature measured by the pyrometer elementsat which the grate motor is' stoppedand the signal horn operated depends on 'the position of the switch 66. The normal operating temperature in the ash bed at the level of the pyrometer tubes is usually about 400 to 500 F., and the switch should beset for a temperature somewhat above the" normal temperature of the ash bed at the level of the tubes but not above about,800F.

There is thus provided means responsive to the temperature of the ash bed at a certain level record sheet when the temperature at any of the measuring points in the ash bed has reached the predetermined maximum, which will indicate to him that the bed at and -near some point in the bed is too'thin, the chart record will show him which particular part of the ash bed is too thin. The operator would then know that the operation of the grate should be stopped so that the-ashbedlwould then. buildup in thickness.

The apparatus opera es; however, to stop the of the ash bed adjacent the grate motor automatically at the same time that the danger signal is sounded. If, therefore, the operator should for any reason not act promptly in response to the signal, the operation of the grate will nevertheless be stopped, thereby preventing further thinning of the ash bed and increase of its temperature toward the grate, and permitting the building up of the bed.

Heat responsive elements, or devices, other than thermo-couple tubes may of course be used, and in Fig. therev is shown an alternative current-generating device comprising a photo-electric cell 65 mounted at the outer end of a. tube 66 of a suitable heat resisting material which may be mounted to extend through the furnace wall into the ash bed like and instead of the tubes 40 in Fig. 1. The cell developes a small electric potential when subjected to radiation from the closed inner end of the tube, which may become heated to low incandescence.

The invention includes, also, means whereby the grate motor will be again started in operation when the too thin portion of the ash bed has, because of non-operation of the grate, been built up to a suitable thickness. This restarting of the motor is effected by taking advantage of the difference between the pressure in the ash.

pit and the pressure in the upper part of the producer chamber or in the gas take-off, when there is no too thin portion of the ash bed. For this purpose, a manometer I0 is provided con- 86. By opening one or more of the valves 83 or the valve 86, steam may be discharged into a portion or portions of the ash bed where the temperature has been shown to be too high, and such selective application of steam, due to its endothermic reaction with the fuel, will result in a very rapid cure of the overheated condition.

It is to be understood that the invention is not to be limited to the illustrative apparatus shown, but that it includes changes inand modifications thereof within the claims.

What is claimed is: e

1. In a gas producer having a fiat grate of the dry, mechanical type and means to operate the grate to continuously discharge ashes therethrough, the improvement which comprises means to maintain an ash bed of determined thickness over the'grate, said means comprising taining an electricity-conducting fluid such as mercury and having one arm connected to the producer ash pit as by tube H and the other arm connected by tube 'llto the gas take-off-pipe 3|. The manometer tube has two electrical contact terminals extending through the tube wall, one at the bottom of the tube and one in its low pressure arm at a suitable height accordin to the pressure difference at which it is desired that the grate shall be started in operation. These contact terminals are connected in circuit with the switch closing solenoid 51. The circuit to the grate motor will, therefore, by operation of this solenoid be closed when the ash bed has been built up sufllciently to cause a drop in pressure from the ash pit to the take-off pipe such as will raise the mercury to the contact terminal in the low pressure arm of 'the manometer. A hand switch 13 is desirably provided in the circuit to the solenoid 51 so that the operator can,

if he desires, open this circuit to prevent the restarting of the grate motor.

It is sometimes desirable, it the overheating at any one or more stations in the ash bed is serious, or under a heavy load condition, to correct the condition of the ash bed quickly without waiting for the bed to build up following stopping of the grate. To provide for such quick reduction of excessive temperature in any part of the bed, the producer furnace is, in accordance with the in,- vention, provided with a plurality of steam discharge nozzle pipes 80 mounted adjacent to the pyrometer tubes 40 to discharge steam jets into the ash bed. Each of these nozzle pipes 80 is connected by a pipe 8| to a steam header pipe 82 extending about the ash pit wall and to which steam is-supplied from the steam drum 85 or- .i'rom-other suitable source, and each pipe 8| has a shut-off valve 83. A nozzle pipe 84 is also provided extending up through the hollow post Hi to discharge a jet of steam into the middle portion pyrometer tube 4|, and this nozzle 84 is connected to the header pipe 82 by a pipe 85 containing a control val e between the ash pit space means to continuously measure the temperature of the ash bed at a plurality of points at the same horizontal level above the grate, means actuated by said temperature measuring means at a determined maximum temperature measured at any one of said plurality of points to de-energize said grate operating means, means continuously measuring the pressure differential below the grate and the space above the fuel bed on the grate, and means actuated by said pressure differential measuring means at a determined maximum pressure differential measured thereby to reenergize the said grate operating means.

2. In combination with the improvement of claim 1, manually operative means to inject a cooling gas at any one of a plurality of points within the ash bed lying in the space between the temperature measuring means and the grate.

3. In combination with the improvement of claim 1, a signal means actuated by said temperature measuring means to audibly indicate operation of said means to de-energize the grate operating means.

4., In combination with the improvement of claim 1, a means actuated by said temperature measuring means to visually record the temperature being continuously measured at each of said plurality of points by said temperature measuring means.

5. In a gasproducer, the combination of a flat mechanical grate, means actuating said grate to discharge ashes therethrough, means continuously measuring the temperature of the ash bed on the grate at a plurality of points at a determined horizontal level above the grate, means continuously recording the temperatures measured by said temperature measuring means. means actuated by said recording means at a predetermined maximum temperature at any one of said plurality of points to de-energize the said grate actuating means, means to simultaneously actuate an audible signal means, means continuously measuring the pressure differential between the ash pit space below the grate and the space above the fuel bed on the grate, and means actuated by said pressure differential measuring means on the measuring of a predetermined maximum pressure to re-energize said grate actuating means.

6. The combination of claim 5, wherein in combination therewith means to inject a cooling gas at any one of a plurality of points in the space gap between the grate and said temperature measuring means, are provided, said means being selectively operative manually.

- ALFRED E. BLAKE. 

